In the last few years, the benefits of short, intense workouts have been extolled by both researchers and exer-cise fans as something of a metabolic panacea capable of providing greater overall fitness, better blood sugar control, and weight reduction—all of it in periods as short as seven minutes a few times a week.

In research featured recently in The New York Times, a team led by Scripps Florida biologist Michael Conkright have confirmed that there is something molecularly unique about intense exercise: the activation of a single protein. That protein is known as CRTC2.

The scientists showed that following high-intensity exercise, which enlists the sympathetic nervous system’s “fight or flight” response, CRTC2 integrates signals from two different pathways—the adrenaline pathway and the calcium pathway, to direct muscle adaptation and growth only in the contracting muscle.

Using mice genetically modified to conditionally express CRTC2, the scientists showed that molecular changes occurred that emulated exercised muscles in the absence of exercise.

“The sympathetic nervous system gets turned on during intense exercise, but many had believed it wasn’t specific enough to drive specific adaptations in exercised muscle,” said Dr. Conkright. “Our findings show that not only does it target those specific muscles, but it improves them—the long-term benefits correlate with the intensity of the workout.”

In the genetically altered animal models, this resulted in a muscle size increase of approximately 15 percent. Metabolic parameters, indicating the amount of fuel available to the muscles, also increased substantially—triglycerides went up 48 percent, while glycogen supplies rose by a startling 121 percent.

In an exercise stress test, the genetically altered animals improved 103 percent after the gene was activated, compared to an 8.5 percent improvement in normal animals.

“If you think of the adrenaline system as something that mobilizes resources when you encounter, say, a bear on your way to work, what we found is that the system also gets you ready for your next bear encounter,” Conkright said.The new findings open the door to a range of potential exercise enhancements.

The team is now exploring ways to activate CRTC2 so that even an average exercise routine might be made more beneficial.

Assistant Professor Michael Conkright and his team are exploring ways to activate a specific protein so that even an average exercise routine could be enhanced and made more beneficial.